The subject invention relates to an identification card or similar item which serves as evidence of the identity or status of an object or other entity. More particularly, it relates to an identification card or similar item which has a high degree of security against forgery or tampering, and to methods and apparatus for producing and authenticating such cards. The subject invention relates to, and is an improvement on the invention disclosed in, application Ser. No. 07/979,081; filed: Nov. 20, 1992; to: James R. Marcus.
(As used herein the term "identification card" will preferably refer to an item similar to an identification badge of the type used by businesses to identify their employees, but it is within the contemplation of the subject invention, and as used herein the term "identification card" shall include, without limitation, documents, magnetic disks, CD's, or smartcards, or any other suitable item which may record an image together with related data and which may be associated with an object or other entity to be identified).
The identification of objects or other entities is a problem at least as old as history. In modern times the most prevalent solution to this problem is the identification card which serves to establish the identity of the bearer, as well as usually some characteristic, status, or attribute of the bearer. Examples are the employee badge, as noted above, and, most commonly, the driver license. Typically, such identification cards will include a picture of the nominal bearer as well as relevant information in text form.
While identification cards and the like have generally proven useful for the day to day conduct of affairs nevertheless they are still subject to forgery or tampering, and indeed a moderately sized illegal industry exists for the purpose of providing false identification documents.
For applications where a high degree of security of identification is required, efficient techniques have been developed to recognize fingerprints, voice patterns, retinal patterns, or other characteristics of individuals, such systems are highly successful in uniquely identifying individuals known to the system, but are subject to the disadvantages of requiring highly sophisticated, expensive sensors, which are typically not mobile, and Which must be connected to a database which identifies selected individuals in terms of physical characteristics such as fingerprints. Such a database must generally be centrally located, both to protect if from tampering and to facilitate updating. Thus, these sophisticated systems are generally limited to restricting access to secure areas.
As is apparent from the above discussion the most common application of identification cards is to identify persons. However, the problem of identification may extend to a very broad class of objects or other entities. Thus, it may be desirable to be able to establish that a particular item has been inspected, or passed through customs, or was produced by a particular company. Similarly, it may be desirable to have secure evidence of the provenance of an artwork, or the pedigree of an animal, or that a person, animal, or plant is free from disease. Such applications, and others which will be apparent to those skilled in the art are within the contemplation of the subject invention.
Perhaps because it relates to information, rather than tangible objects, the identification or authentication of documents or other forms of information has been dealt with perhaps more successfully in the past; usually by use of some form of encryption. Thus, U.S. Pat. No. 4,853,961; for: "Reliable Document Authentication System": Pastor; issued: Aug. 1, 1989, discloses a system wherein a document is authenticated by encryption using a public key encryption system. U.S. Pat. No. 4,637,051; to Clark discloses a postage meter having an indicia which authenticated by encryption. Many other applications of encryption to authenticate information will be known to those skilled in the art.
One approach to the problem of providing secure identification cards is disclosed in the above referenced application to Marcus. This applications discloses an identification card which includes an image of an object to be identified (typically a person's face) on one side, and an encrypted signal representing a compressed representation of that image on the other side. To validate the card the encrypted data is decrypted and a representation of the print image is generated and displayed for comparison with the printed image on the first side.
While this technique has been demonstrated and is generally considered satisfactory, it suffers from the disadvantage that, even with compression, the representation of the image required a large amount of data, typically more than 1000 bytes This amount of data requires sophisticated, high-density coding techniques, such as the known PDF-417 two-dimensional bar code, to allow all of the data to be incorporated onto a standard sized identification card.
Thus it would be desirable if the amount of data which is needed to encode the representation of the image could be reduced so that, for example, the representation of the image could be recorded on magnetic stripes such as those that are commonly used on standard credit cards.
Thus it is an object of the subject invention to provide an identification card to identify an object or other entity, which card is secure against tampering and forgery, and which card requires a substantially reduced amount of data to record the representation of the image.